| 201 | Hallwood Petroleum, Inc. | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 202 | Hampton Resources Corporation | Houston, TX 77010 | Oil & Gas Operator | Mar 1996 |
| 203 | Harvest Oil & Gas, LLC | | Oil & Gas Operator | Feb 2012 |
| 204 | Hassie Hunt Expl. Co. | | Oil & Gas Operator | Aug 2008 |
| 205 | Helis Oil & Gas Company, L.L.C. | New Orleans, LA 70130 | Oil & Gas Operator | Oct 2023 |
| 206 | Henderson Petroleum Corp | San Angelo, TX 76906 | Oil & Gas Operator | Jul 2013 |
| 207 | Hess Corporation, A De Corp. | | Oil & Gas Operator | Oct 2006 |
| 208 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Dec 2025 |
| 209 | Hilliard Oil & Gas, Inc. | New Orleans, LA 70112 | Oil & Gas Operator | May 2001 |
| 210 | Hillside Oil & Gas, LLC | Midland, TX 79708 | Oil & Gas Operator | Apr 2016 |
| 211 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Dec 2025 |
| 212 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 213 | Hubco Exploration Inc. | Houston, TX 77073 | Oil & Gas Operator | Sep 2002 |
| 214 | Huffco Petroleum Corporation | | Oil & Gas Operator | Jul 1988 |
| 215 | Hughes Denny Offshore Expl Inc | | Oil & Gas Operator | Nov 1988 |
| 216 | Hughes Eastern Petroleum, Inc. | | Oil & Gas Operator | Apr 1993 |
| 217 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Dec 2025 |
| 218 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 219 | Hunt Petroleum Corp. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 220 | I.G. Petroleum, L.L.C | | Oil & Gas Operator | Dec 2018 |
| 221 | Indrex Inc | Tulsa, OK 74133 | Oil & Gas Operator | Dec 2000 |
| 222 | Inexco Oil Company | Houston, TX 77210 | Oil & Gas Operator | Mar 2013 |
| 223 | J F D Inc | Houston, TX 77041-6914 | Oil & Gas Operator | Feb 2000 |
| 224 | J-O'B Operating Company | Shreveport, LA 71135 | Oil & Gas Operator | Dec 2025 |
| 225 | J.A. Seglund,Inc. | | Oil & Gas Operator | May 1982 |
| 226 | J.R. Vann | | Oil & Gas Operator | Dec 1979 |
| 227 | Jack Corman | | Oil & Gas Operator | Jul 1981 |
| 228 | James A. Whitson, Jr. | | Oil & Gas Operator | Apr 2016 |
| 229 | Jetta Operating Company, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Dec 2025 |
| 230 | John W. Mecom | | Oil & Gas Operator | Mar 1991 |
| 231 | Jones-O'Brien, Inc. | | Oil & Gas Operator | Feb 1982 |
| 232 | June Energy Inc. | | Oil & Gas Operator | May 2000 |
| 233 | Karbuhn Oil Company | Tomball, TX 77375 | Oil & Gas Operator | Dec 2025 |
| 234 | Kedco Management Corp | | Oil & Gas Operator | Jul 1985 |
| 235 | Kele Exploration, Inc. | | Oil & Gas Operator | Apr 1990 |
| 236 | Kelly H Baxter | Austin, TX 78767 | Oil & Gas Operator | Nov 2006 |
| 237 | Kelly Oil Co Inc | | Oil & Gas Operator | Sep 2013 |
| 238 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Aug 2025 |
| 239 | Kerr-McGee Oil & Gas Corp. | Houston, TX 77251 | Oil & Gas Operator | Sep 2006 |
| 240 | Kewanee Oil Company | Houston, TX 77001 | Oil & Gas Operator | Aug 1978 |
| 241 | Key Operating Company Inc | Duncan, OK 73534-1284 | Oil & Gas Operator | Jan 2025 |
| 242 | KFS Investments, L.L.C. | | Oil & Gas Operator | Jul 2009 |
| 243 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |
| 244 | Konantz, Inc. | | Oil & Gas Operator | Jan 1995 |
| 245 | L & W Oil & Gas, Inc. | | Oil & Gas Operator | May 1994 |
| 246 | La. Land & Expl. Co. | | Oil & Gas Operator | Dec 2010 |
| 247 | La. Mining & Minerals, Inc. | | Oil & Gas Operator | Jul 2000 |
| 248 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 249 | Laurel Operating Company | Stillwater, OK 74074-3025 | Oil & Gas Operator | Aug 2025 |
| 250 | Lavaca River Operating Co., LLC | The Woodlands, TX 77381 | Oil & Gas Operator | Dec 2025 |
| 251 | LGS Exploration Program | | Gas Operator | Jul 1990 |
| 252 | LGS Exploration, Inc. | | Oil & Gas Operator | Jan 1991 |
| 253 | LHC Petroleum Corporation | | Oil & Gas Operator | Jul 2001 |
| 254 | Liberty Oil & Gas Corp | Olney, IL 62450-2489 | Oil & Gas Operator | Dec 2021 |
| 255 | Linder Energy/La General Oil | | Oil & Gas Operator | Mar 1989 |
| 256 | Linder Oil Company,A Partnership | Shreveport, LA 71136 | Oil & Gas Operator | Dec 2025 |
| 257 | Llog Expl. Co. | Metairie, LA 70005 | Oil & Gas Operator | Jan 2003 |
| 258 | Llog Exploration Company, L.L.C. | | Oil & Gas Operator | Sep 2025 |
| 259 | Llox, L.L.C. | Covington, LA 70433 | Oil & Gas Operator | Dec 2025 |
| 260 | Lobo Operating, Inc. | Houston, TX 77077 | Oil & Gas Operator | Dec 2024 |
| 261 | Long Acres Prod. Co., Inc. | | Oil & Gas Operator | Aug 1986 |
| 262 | Louisiana Crude Oil&Gas Co Inc | | Oil & Gas Operator | Mar 1984 |
| 263 | Louisiana Gas Service Co. | | Oil Operator | May 2004 |
| 264 | Lse Energy Operating Co. Inc. | | Oil Operator | Jun 1996 |
| 265 | Maddox Energy Corp | Dallas, TX BAD ADDR | Oil & Gas Operator | Jul 1995 |
| 266 | Magnum Minerals, Inc. | | Oil & Gas Operator | May 1998 |
| 267 | Magnum Producing, LP | Corpus Chrsti, TX 78401 | Oil & Gas Operator | Dec 2025 |
| 268 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 269 | Manti Exploration Operating LLC | Corpus Chrsti, TX 78403 | Oil & Gas Operator | Feb 2015 |
| 270 | Manti Operating Company | Covington, LA 70435 | Oil & Gas Operator | Dec 2025 |
| 271 | Mariner Energy, Inc. | Houston, TX 77042 | Oil & Gas Operator | Nov 2010 |
| 272 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 273 | Maritech Resources, LLC | | Oil & Gas Operator | May 2011 |
| 274 | Marks Operating LLC | | Oil & Gas Operator | Jul 2016 |
| 275 | Marlin Energy Offshore, L.L.C. | | Oil & Gas Operator | Jun 2006 |
| 276 | Marquis Resources, LLC | | Oil & Gas Operator | Jul 2021 |
| 277 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 278 | Martin Energy LLC | | Oil & Gas Operator | Apr 2023 |
| 279 | Martin Exploration Co. | | Oil & Gas Operator | Apr 1986 |
| 280 | Martin-Marks Operating Co. LLC | | Oil & Gas Operator | Dec 2010 |
| 281 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 282 | Matrix Oil & Gas, Inc. | | Oil & Gas Operator | Jul 2001 |
| 283 | May Petroleum Inc | Dallas, TX 75231 | Oil & Gas Operator | Nov 1998 |
| 284 | McAlester Fuel Co. | Houston, TX 77042 | Oil & Gas Operator | Jan 2010 |
| 285 | McGoldrick Oil Company | Shreveport, LA 71129 | Oil & Gas Operator | Jul 2020 |
| 286 | McGowan Working Partners | Jackson, MS 39296 | Oil & Gas Operator | Dec 2000 |
| 287 | McGowan Working Partners, Inc. | Jackson, MS 39296 | Oil & Gas Operator | Dec 2025 |
| 288 | McMoran Exploration Company | | Oil & Gas Operator | May 1985 |
| 289 | McMoran Oil & Gas LLC | New Orleans, LA 70160 | Oil & Gas Operator | Oct 2021 |
| 290 | McMoran Production Co. | | Oil & Gas Operator | May 1985 |
| 291 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 292 | Mesa Gulf Coast LLC | | Oil & Gas Operator | Dec 2020 |
| 293 | Micron Minerals Company | | Oil & Gas Operator | Sep 1988 |
| 294 | Mid Louisiana Gas Company | | Oil & Gas Operator | Oct 2002 |
| 295 | Milagro Exploration, LLC | Houston, TX 77010 | Oil & Gas Operator | Aug 2018 |
| 296 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 297 | Moore McCormack Energy, Inc. | | Oil & Gas Operator | Jul 1988 |
| 298 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 299 | Mullins & Prichard | | Oil & Gas Operator | May 1992 |
| 300 | National Offshore LP | Oklahoma City, OK 73154 | Oil & Gas Operator | Mar 2008 |